1. Field of the Invention
The present invention relates to a door frame system for a glass door of a building, and more particularly, to a door frame system, which includes a fixed bench not moving when assembled, a horizontally movable pressure bench, a compression rail pushing the pressure bench in a horizontal direction only, and a frame to which the fixed bench, the pressure bench, and the compression rail are assembled, so that the assembled frame is combined with a glass pane.
2. Background Art
U.S. Pat. No. 6,434,905 issued on Aug. 20, 2002 discloses a door rail system. Referring to FIG. 15, the door rail system of the prior art includes: a housing 102 having inclined slide surfaces 122 narrowing downwardly; a pair of clamp members 104a and 104b, each having an inclined friction surface 120 in parallel with the inclined slide surface 122; a nut strip 108 coupled with a bolt 106 pulling the clamp members 104a and 104b in one direction so as to simultaneously close the clamp members 104a and 104b, so that the clamp members can be combined with the glass pane 101.
In more detail, the housing 102 includes the inclined slide surfaces 122 formed at both sides of the upper space thereof in a downward direction and double-layer type bridges 116 and 118. Each clamp member includes the inclined friction surface 120 sliding on the inclined slide surface 122 and a recess 104a′ or 104b′ formed at the lower portion thereof. An elongated nut strip 108 which has at least two female screw holes 108a is located in the recess 104a and 104b, and a bolt 106 passes through holes 116a and 118a perforating the bridges 116 and 118 of the housing 102 and inserted into the female screw hole of the nut strip 108.
A process for manufacturing the door rail system of the prior art is described below. First, the clamp members 104a and 104b are coupled with each other in such a way that the inclined friction surfaces 120 are respectively in contact with the inclined slide surfaces 122 of the housing 102, and the recesses 104a′ and 104b′ face with each other, and then, the elongated nut strip 108 is pushed into the recesses 104a′ and 104b′. 
Next, the bolt 106 is inserted into the through holes 116a and 118a, and then, rotated in such a way as to be fit into the female screw hole 108a of the nut strip.
The housing 102 to which the above components are assembled is combined to the upper surface and the lower surface of the glass pane 101 put on a table.
The combining method is as follows. Both ends of the clamp members 104a and 104b are adjusted to be fit with both ends of the housing 102, and then, the bolt 106 is loosened or tightened in such a way that the glass pane 101 is fit between the clamp members 104a and 104b. After an interval between the clamp members 104a and 104b is adjusted, the clamp members 104a and 104b are fit to the ends of the glass pane 101 in a state where two workers grasp both ends of the glass pane 101, so that the clamp members 104a and 104b do not separated out from the inside of the housing 102. After that, one worker grasps the housing 102 and the other tightens the bolt 106 so as to combine the housing 102 with the glass pane 101.
As described above, in the prior art, the glass pane is assembled with the housing according to such difficult method, however, when the bolt 106 is tightened to completely assemble the housing 102 to the glass pane 101, the clamp members 104a and 104b are unsteadily tightened and do not keep a straight line condition with the glass pane 101 while the bolt 106 is tightened.
Furthermore, the clamp members 104a and 104b are pulled outwardly from the ends of the glass pane 101 while the bolt 106 is tightened. So, finally, the door becomes longer than a set length of a standard door and is not up to the standard, so that workers must repeat attaching and detaching action of the door till the door is fit to a doorframe of a building when the door is installed to the building.